A horrific four-car smashup – which began when a vehicle jumped the median and careened into oncoming traffic on the Bronx River Parkway – left five people dead yesterday, including a 7-year-old girl.

“Help me, Jesus! Help me!” wailed one of the devastated mourners last night outside Jacobi Hospital, where the dead and injured were taken.

Stunned, sobbing relatives and friends crowded into the waiting room.

The disastrous chain of events began around 2:30 p.m. when a green Acura Legend loaded with seven passengers slowed down in heavy traffic in the southbound lanes.

Somehow, the driver lost control of the luxury car near 180th Street and vaulted onto the divider in the middle of the highway, police said.

It rode along the median for 200 feet, cops said, knocking out a lamppost in its wild ride.

The Acura then went flying into the northbound lane of the parkway – and collided head-on with an Access-a-Ride bus and a Toyota Corolla.

A Lincoln Town Car limousine with two passengers in it then hit the Accessa-Ride bus, which was empty except for the driver.

All of the fatalities were in the Acura, police said.

Three men and the 7-year-old girl were killed instantly and the driver died shortly after at Jacobi.

The other two passengers were in critical condition.

Police did not release the names of the crash victims.

Witness Kristyn Weeks, 38, said she ran to the Acura to try to help.

“There was a bad scene,” she said of the mangled vehicle. “People were not alive. But there were signs of life [in the other car].

Two men seemed like they were trying to breathe.” Weeks called 911 and then ran to help the three passengers from the Toyota, who were sitting on the side of the highway, bleeding, bruised and in shock.